1. Field of the Invention
The present invention relates to an air conditioning apparatus having a dehumidifying operation function of removing moisture from air in a room.
2. Description of the Related Art
There is known an air conditioning apparatus which is equipped with two indoor heat exchangers connected by a parallel combination of an expansion valve and a two-way valve.
With this type of air conditioning apparatus, opening the two-way valve to thereby cause the flow of a refrigerant to bypass the expansion valve permits the indoor heat exchangers to function as a single heat exchanger. On the other hand, closing the two-way valve to thereby apply the expansion valve between the indoor heat exchangers permits each of the heat exchangers to serve as a separate heat exchanger.
Thus, opening the two-way valve so as to cause each of the indoor heat exchangers to serve as an evaporator will perform cooling operation. Opening the two-way valve so as to cause each of the heat exchangers to serve as a condenser will perform heating operation. Closing the two-way valve to thereby cause one of the indoor heat exchangers to serve as a condenser (a reheater) and the other to serve as an evaporator will perform dehumidifying operation. That is, the air in the room is cooled and dehumidified by the evaporator and then discharged into the room after being reheated by the condenser.
An example of such an air conditioning apparatus equipped with functions of cooling operation, heating operation and dehumidifying operation is disclosed in Japanese Examined Patent Publication No. 52-45418. Also, there is disclosed in U.S. Pat. No. 4,905,894 a refrigerant heating type air conditioner that is equipped with a refrigerant heating device and performs heating operation by utilizing heat of combustion by the heating device.
A problem with such an air conditioning apparatus in which the functions of the two indoor heat exchangers are switched by opening and closing of the two-way valve as described above is that the refrigerant produces a loud sound when the two-way valve is opened or closed. This sound will make people in the room unpleasant.